Cathodic sputtering device

ABSTRACT

A target for a cathode sputtering device for producing coatings on a substrate (27) by a sputtering cathode (2), which can be introduced into a vacuum chamber, the target having a center axis (44) and being dynamically balanced with respect to the center axis (44) and having a back surface (40) and a target surface (41), the target surface (41) being spaced from the back surface and being concave as a new target surface. The target surface (41) is formed by at least two concentric target surface portions which are inclined with respect to each other, the target surface portions including an outer, radially inwardly extending target surface portion (49, 76) enlarging conically away from the center axis in a direction away from the back surface, and an inner, radially outwardly extending target surface portion (78&#39;) narrowing conically toward the center axis in the direction away from the back surface. The target surface (41) has a radially outer edge delimited by an axially projecting edge (72) being inclined with respect to the center axis (44). A concentric target surface intermediate portion (50) extending in a plane perpendicular to the center axis (44) is provided between the outer target surface portion (49) and the axially projecting edge (72).

This application is the national phase of international applicationPCT/EP97/01871 filed Apr. 14, 1997 which designated the U.S.

BACKGROUND OF THE INVENTION

The present invention relates to a device for cathode sputtering forproducing coatings on a substrate by means of a sputtering cathode,which can be introduced into a vacuum chamber and has magnets or ringmagnets, pole shoes and a target extending concentrically with thecenter axis of the sputtering cathode, and whose surface extends atleast partially inclined with respect to the back of the target.

A device for cathode sputtering for the static coating of disk-shapedsubstrates by means of a plasma in a vacuum chamber with at least oneopening, which can be closed from the outside by placing a sputteringcathode on it, is already known (DE 43 15 023 A1). An elastic vacuumseal ring and an annular anode are provided between the cathode and thechamber wall, which radially enclose the openings from the outside,wherein the anode has a flat contact surface on its side facing in thedirection of the cathode. The known sputtering cathode consists of adisk-shaped ferromagnetic yoke and a cooling plate. A disk-shapedinsulator is inserted between these two. The target to be sputtered isarranged in front of the cooling plate, while a ring magnet is insertedin a groove on the back of the cooling plate. A counter-magnetic fieldis generated by the ring magnet, which affects the path of the magneticfield lines. By means of this, the path of the magnetic field lines isgiven an approximately parallel or lens-shaped or convex form.

BRIEF SUMMARY OF THE INVENTION

In contrast thereto, it is an object of the present invention to arrangeor design the target surface in such a way that the target yield isimproved. This object is achieved by the features of the claims.

In achieving this object, the invention starts out from the basic ideaof providing a specific target geometry which allows a longer servicelife. In particular, the target comprises an inclined raised edge onboth the inner and outer edges of the sputtering surface in order toimprove the electron enclosure.

In accordance with the invention, the object is achieved in that atarget surface extending inclined with respect to the back surface ofthe target or at least part of this surface encloses an angle with theback surface of the target, and the target surface is located betweenfurther target surfaces also including an angle with the inclinedextending target surface. Thus, the target yield can be optimized sincethe surface of the target takes a course being adapted to the magneticfield lines. This is also achieved in that due to the advantageousdesign of the target surface, the magnetic field lines take a flatcourse. The inclined extending surface on the target or the convextarget surface causes the material to be focussed from a larger targetto a smaller substrate. Due to the parallel course of the partial targetsurfaces, a material accumulation for the target is provided. To thisend it is advantageous that the magnetic field is adapted to this targetdesign, i.e. takes a course which is almost parallel with the targetsurface.

To this end it is advantageous that the target surface extendinginclined with respect to the back surface of the target is locatedbetween target surfaces enclosing an angle with it, said angle having avalue of more than 10°.

In a further development of the invention it is advantageous that thetarget surface extending inclined with respect to the back surface ofthe target is located between target surfaces enclosing an angle withit, said angle having a value between 10° and 40°, or between 15° and40°, or between 20° and 40°, and that a dynamically balanced annulargroove adjoins the inner end of the inclined extending target surface.

Moreover, according to a preferred embodiment of the solution accordingto the present invention, the inner end of the inclined extending targetsurface adjoins a dynamically balanced annular groove or V-shapedannular groove having an angle between 10° and 40°.

It is of particular importance for the present invention that the upperend being located in the area of the target surface makes a transitioninto an outwardly directed element or a sharp-edged nose.

In connection with the design and arrangement according to the inventionit is advantageous that the nose encloses an angle which can have avalue between 20° and 60° or between 25° and 55° or between 30° and 40°or between 38° and 44°.

It is furthermore advantageous that the V-shaped dynamically balancedannular groove encloses an angle having a value between 30° and 50°.

Moreover, it is advantageous that the width of the edge element having anose is smaller than the width of the annular surface extending parallelwith the back surface of the target or smaller than the width of theinclined extending surface.

To this end it is advantageous that the width B₁ is approximately twiceas large as the width B₂ and twice as large as the width B₃.

Moreover, it is advantageous that the angle between the inclinedextending surface and the front surface of the target has a valuebetween 18° and 34° or between 20° and 32° or between 23° and 29° or of26°.

It is also advantageous that in the area of the back surface of thetarget a second outer ring magnet having a larger diameter is providedbesides the first inner ring magnet. By employing two ring magnets it ispossible to achieve an increase in the magnetic field and simultaneouslyin a defined area of the cathode a flat surface path for the magneticfield lines with respect to the back surface of the target. An improvedutilization of the target is assured by this.

To this end it is furthermore advantageous that the two ring magnetsprovided in the area of the back surface of the target are arranged onthe same transverse plane, and that the inner ring magnet is provided inthe area of the exterior circumference of the center mask or the centeranode or a cooling finger, and the outer ring magnet in the edge area orin the area of the exterior circumference of the target.

In a further development of the invention it is advantageous that,besides the two inner ring magnets, a third ring magnet is provided. Thethird ring magnet surrounds the two ring magnets and adjoins a side orthe bottom side of the yoke.

In accordance with a preferred embodiment of the invention, all ringmagnets are mounted to be dynamically balanced with respect to the-enter axis of the target and the two inner ring magnets are provided inannular grooves situated in the cooling plate. The laterally disposedring magnet generates the magnetic sputering field which penetrates thetarget.

In accordance with a further feature of the device according to theinvention, the outer ring magnet is optionally provided in the area ofthe pole shoe diameter between the yoke and the upper part of the poleshoe, and the two inner ring magnets are optionally located inside theexterior diameter or the exterior circumference of the target.

It is furthermore advantageous to have the outer ring magnet at a largerdistance from the back surface of the target than the two inner ringmagnets, and that a fourth ring magnet is provided which encloses theexterior circumference of the target. By means of the installation ofthe additional double ring magnets, which can also be placed very closeto the back surface of the target, the widest possible erosion ditch iscreated since the electrons are not being focussed on narrow areas or ona narrow annular groove. For this reason it is advantageous that a largehorizontal component of the magnetic field is achieved, and a very shortdistance from the back of the target is achieved by installing thedouble ring magnets in the rear wall of the cooling plate. The targetconfiguration and the pole shoe design are also of particularimportance.

To this end it is advantageous that the thickness D₁ of the target atits outer edge area is greater than the thickness D₂ at the inner edgearea of the target, and that an inclined extending target surface and atarget surface extending parallel with the back of the target areprovided between the inner and the outer edge areas of the target.

It is furthermore advantageous that the inclined extending targetsurface is provided in the inner edge area of the target, the parallelextending target surface is provided in the outer edge area of thetarget, and the inclined extending target surface and the parallelextending target surface are provided between inner and outer targetelements protruding in the form of sharp edges.

In accordance with a further development of the device of the invention,a further option consists in that a ring-shaped flange element extendingconcentrically with the center axis is provided at the inner edge areaof the target, which flange element is clamped between the surface ofthe cooling plate and the flange element of a cooling finger, which isfixedly or releasably connected with the target. Because of theadvantageous design of the target with a flange-shaped element inconnection with a cooling finger, which can be screwed in or fixed inplace by means of screw elements, the target no longer needs to bebonded on, but can be easily replaced at any time as required.

Depending on the use, it is also possible that at least one ring magnetis provided in the area of the exterior circumference of the targetbelow the ring magnets provided at the back of the target or in itsarea.

To this end it is furthermore advantageous that the ring magnet providedin the area of the exterior circumference of the target is providedslightly above the lower limit of the target surface, and that the ringmagnet provided in the area of the exterior circumference of the targetis provided slightly outside the lower limit of the target surface whichextends parallel with the back surface of the target.

In a further development of the invention, it is advantageous that thering magnet provided in the area of the exterior circumference of thetarget terminates slightly below or outside the lower limit of the poleshoes, that the ring magnet is disposed concentrically with respect tothe center axis of the target and that the lower end of the pole shoe isat a greater distance from the back of the target than the lower end ofthe target or the target surface.

In this way it is assured that the lower part of the pole shoe isprovided with an annular space or a chamber for housing the outer ringmagnet, and that the lower part of the pole shoe toward the exteriorcircumference of the pole shoe consists of a pole shoe element whichtapers in the form of a truncated pyramid.

It is of special importance for the present invention that the pole shoeelement which tapers in the form of a truncated pyramid makes atransition into the flange element which is wider than the free-standingend of the pole shoe, and that the flange element of the pole shoe formsone chamber wall of the ring magnet.

In connection with the embodiment and arrangement according to theinvention, it is advantageous that an angle (α) is formed between thefront face of the end of the pole shoe and the inclined extendinglateral wall of the pole shoe element which tapers in the form of atruncated pyramid, which angle has a value between 10° and 50° orbetween 25° and 45° .

It is furthermore advantageous that the distance between the outer ringmagnet and the lower end or front face of the target is about 20% to 40%of the thickness D₁ of the target. An optimal design of the target isachieved because of the inclined extending arrangement of the target andthe adjoining parallel extending target surface, in particular if anon-ferromagnetic metal or aluminum target is employed as coatingmaterial, since because of the advantageous arrangement of the ringmagnets, more material is sputtered off in the outer area of the targetthan in the inner area. This therefore provides an even use of thetarget.

Further advantages and details of the invention are described in theclaims and the description and are shown in the Figures, wherein it ispointed out that all individual features and combinations of individualfeatures are essential for the present invention.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

FIG. 1 is a cross-sectional view of a target with numerousconcentrically arranged ring magnets,

FIG. 2 is a partial view of the pole shoe according to FIG. 1,

FIGS. 3-7 show further embodiments of targets with surfaces having adifferent design,

FIG. 8 shows vectors which make clear the electron emission.

DETAILED DESCRIPTION OF THE INVENTION

A cathode sputtering device for producing coatings on a substrate, e.g.a compact disk 27, is represented in FIG. 1. For performing the process,the sputtering cathode 2 can be installed in a chamber wall 1 of thecathode sputtering device. The cathode is composed of a disk-shapedferromagnetic yoke 5 and a cooling plate 7. An insulator 6 is clampedbetween the yoke 5 and the cooling plate 7 and secured by means ofthreaded bolts.

A target 8 to be sputtered is arranged in front of the cooling plate 7.A ring-shaped, or annular, groove 66 and an annular groove 65 are alsoformed in the back of the cooling plate 7 for housing an inner ringmagnet 9 and an outer ring magnet 42 which are arranged concentricallywith respect to the center axis 44 of the target 8. The yoke 5, theinsulator 6 and the cooling plate 7 are secured by means of a screw,which is not shown in the drawings. In an advantageous manner the screwis insulated against the yoke by means of an insulator. A cableconnected with a sputter current supply device can be connected with thescrew.

A further ring magnet 13 arranged concentrically with respect to thecenter axis 44 is located in the area of the exterior circumference ofthe cooling plate 7 or the insulator 6. The magnet 13 is embodied as aferromagnet and therefore constitutes the complete magnetic fieldenclosure.

A pole shoe 14, which concentrically surrounds the insulator 6, thecooling plate 7 and the target 8, adjoins the ring magnet 13.

The lower part of the pole shoe forms a pole shoe element 60 in the formof a truncated pyramid, or cone, tapering downwardly or in the directiontoward the vacuum chamber. The lower portion of pole shoe element 60 inthe form of a truncated pyramid makes a transition into a ring-shapedflange element 61 which is wider than the free-standing end 62 of thepole shoe. The flange element 61 of the pole shoe 14 has the lateralwall 63 or the front face which is part of the pole shoe element in theform of a truncated cone. Two annular flanges 61 disposed at a distancefrom each other can be attached to the lower end of the pole shoe andform an annular chamber 59.

If a fourth ring magnet 47 is received concentrically with respect tothe center axis 44, the annular flanges 61 may be omitted.

An angle α, which can have a value between 10° and 60°, or 20° and 50°,or 25° and 45°, and which affects the course of the magnetic field linesin an advantageous manner, is formed between the front face of the end62 of the pole shoe 14 and the inclined extending lateral wall 63 of thepole shoe element 60 in the form of a truncated pyramid.

A bore 67 is located in the area of the center axis 44 of the sputteringcathode 2, which bore 67 extends through the entire device and is usedto receive a hollow screw 20 which is pushed or screwed in place so thatits lower flange element 54 bears against a flange element 53 providedon the target 8.

With a yoke plate 21, the yoke 5 adjoins the hollow screw 20 in theaxial direction without contacting hollow screw 20.

A cooling head is fastened on the back of the yoke 5 by means of aflange 22 and extends in the axial direction through the yoke plate 21as well as through the hollow screw 20 up to the front of the target anddoes not contact the hollow screw 20. The flange 22 of the coolingfinger 69 with the cylindrical element adjoining it forms a cylindricalbore 70 for receiving a tube, not shown in the drawings, which isconnected to a cooling water line.

A center mask or center anode 26 is releasably connected by means of ascrew 25 to the front face or the lower end of the flange 22 of thecooling finger 69. The center anode 26 extends as far as the hollowcenter of the target 8 which is provided at the front of the target; thelower end of center anode 26 forms, together with an outer anode 4 orouter mask, an annular surface for masking the substrate 27.

As can be seen from FIG. 1, the screw 20 has the flange element 54 whichpushes the flange element 53 provided at the target 8 against the frontof the cooling plate 7. In this way the otherwise customary bonding ofthe target can be omitted, and it can easily be replaced. It isfurthermore possible to connect the target with the cooling flange bymeans of screws.

As can be seen from FIG. 1, the two ring magnets 9 and 42 provided onthe back of the target are arranged preferably in the same transverseplane. The inner ring magnet 9 is arranged in the area of the exteriorcircumference 56 of the center mask or center anode 26 or of the coolingfinger 69 or closer toward the center axis 44 or in the area of theexterior circumference of the hollow-shaped screw 20 for receiving thecooling finger 69. The outer ring magnet 42 is situated in the edge areaor in the area of the exterior circumference 55 of the target 8.

The ring magnet 13 is located slightly above the two ring magnets 9 and42 and can be disposed on the yoke 5. The ring magnet 13 can be formedby numerous individual magnets arranged in a ring-shape.

Depending on the development of the target, which can be embodied, forexample, as an aluminum target or a gold target, a fourth ring magnet 47can be provided in the area of the lower end of the exteriorcircumference of the target 8.

All ring magnets 9, 13, 42 and 47 are mounted to be dynamically balancedabout the center axis 44 of the target 8. In an advantageous manner, thetwo inner ring magnets 9 and 42 are also located inside the exteriordiameter or exterior circumference 55 of the target 8.

As can be seen from FIG. 1, the outer ring magnet 13 is at a greaterdistance from the back of the target than are the two inner ring magnets9 and 42.

If, for example, the target is embodied as an aluminum target, it isadvantageous for the thickness D₁ of the target 8 at its outer edge 55to be greater than the thickness D₂. By means of this, the target 8 isgiven an inclined extending target surface portion 49 in accordance withFIG. 1, and an adjoining target surface portion 50 extending parallelwith the back of the target.

If an aluminum target is used and two double ring magnets are employed,the magnetic field is flattened at the back of the target, even with avery compact design (in this connection see the magnetic field lines 71of the right-hand side of the target 8). If, for example, the two doublemagnets were omitted, the magnetic field lines 71' would take a veryunfavorable course, i.e. they would enter the yoke 5 almost vertically.On the right-hand side of FIG. 1, the field lines 71 take a convex orflattened or approximately parallel course with respect to the back ofthe target. This is caused in an advantageous manner by the two doublering magnets 9 and 42 provided at the back of the target, which aid inthe amplification of the field lines. Such an arrangement of the ringmagnets 9 and 42 is particularly suitable in connection with anon-ferromagnetic metal target, for example an aluminum target. A verycompact design of the entire device is achieved because of the doubleembodiment of the two ring magnets and the danger of a short circuit isruled out to a large degree. Thus, the two ring or counter magnets 9 and42 amplify the magnetic field lines so that they can take up the courseshown on the right-hand side of FIG. 1.

As can be seen from FIG. 1, the distance A between the front face of thecooling plate 7 and the lower edge of the center mask and/or anode 26 isgreater than the thickness D₁ of the target 8 or the distance P betweenthe back 40 of the target and the sharp-edged, projecting pole shoeelement 62.

A sharp-edged target element 51 located in the center or in the area ofthe center axis 44 is set back in relation to the exterior targetelement 52.

If, for example, a target with a low electron emission rate or a goldtarget is employed, it is advantageous if the magnetic field isamplified in the area of the target surface, because a gold target has aconsiderably different sputtering property than an aluminum target. Thering magnet 47 provided in the area of the exterior circumference of thetarget 8 and in the pole shoes 14 is situated in the area or slightlybelow the target surface 41 and is used for amplifying the magneticfield in the area of the target surface 41, so that with thisarrangement, too, the magnetic field lines do not enter the yoke 5vertically or approximately vertically. This relatively large magnet 47lies in the direction of the main magnetic field and aids in theamplification of the magnetic flux. In this case the flanges or bars 61of the pole shoe element 62 can be omitted.

Since a lesser electron emission occurs with gold sputtering, a clearlyhigher voltage of, for example, 2,000 V would be required without therelatively large ring magnet in the vicinity of the target surface 41 inorder to provide an output worth mentioning. By means of theadvantageous provision of the ring magnet 47, the magnetic field can beamplified and the plasma impedance reduced.

The ring magnets 9, 13, 42 shown in FIG. 1 are all polarized in the samedirection, wherein North is directed downwardly, each with respect tothe view of FIG. 1.

FIGS. 3 to 5 show different sputtering cathodes 2 with different targetsurfaces 41.

The magnetic field lines can be influenced by the arrangement of thering magnets. A concentration of the magnetic field lines can, forexample in the area of the target surface, be achieved by the twospaced, parallel flanges or bars 61 (FIG. 1). A wide erosion ditch canbe achieved in that the magnetic field lines extend approximatelyparallel with the area of the back of the target. Therefore, it would bemost advantageous if the magnetic field would adapt to the targetsurface in order to thus achieve a wide erosion ditch. To this end it isadvantageous that in the edge area of the target sharp-edged edges ornoses 72 are provided. The noses 72 can also have a rectangularcross-section with respect to the cross-section of the cathode, i.e.side 72 extends parallel with the edge portion 84 and right-angled withthe target surface 82.

The sharp-edged edges or noses 72 include an angle α₁ between the targetsurface 73 or its external circumference and the surface 76 of the nose72, said angle having advantageously a value of 40°, however alsobetween 20° and 60° or between 25° and 55° or between 30° and 55° orbetween 38° and 54° or also of 50°.

The nose 72 adjoins the small annular surface 50 extending vertical withrespect to the center axis 44 of the target and being mounted to bedynamically balanced about the center axis 44, like the nose 72 alsoforming an annular element. This annular surface 50 is arranged closerto the front surface 75 of the target than to the back surface 74 of thetarget and makes a transition into the inclined extending surface 76 ofthe nose 72.

A further inclined extending target surface 41 adjoins the annularsurface 50 and, together with the nose 72, forms an approximatelyconcave annular surface and ends slightly in front of the center axis 44or a central bore 83 of the target 2.

A sharp-edged nose 78 with a target surface portion 78' adjoins theinclined extending target surface 41 also in the direction of the frontsurface 75 of the target; together with the inwardly inclined extendingtarget surface 41, said target surface portion 78 ' forms a V-shapeddynamically balanced annular groove 79 which encloses an angle μ havinga value between 10° and 50°, preferably between 30° and 50°, or morethan 90°, preferably 125°. A cone angel α₃ between inner target surfaceportion 78' and the center axis 44 has a value between 20° and 70°, morepreferably between 30° and 60°, and most preferably of 60°.

As can be seen in FIG. 3, the edge portion with the nose 72 has a widthB₃ which is smaller than the width B₂ of the annular surface or thewidth B₁ of the inclined extending surface 49.

The width B₁ is approximately twice as large as the width B₂, and twiceas large as the width B₃.

The angle β between the inclined extending surface 49 and the frontsurface 75 of the target has a value of 15° to 35°, preferably 20° to32°, more preferably 23° to 29° and most preferably 25°.

The inner edge of the V-shaped annular groove 79 is locatedapproximately in the center between the back surface 74 of the targetand the front surface 75 of the target.

A particularly preferred target has the following dimensions (see FIG.3):

target thickness (without outer edge 72) T_(D) =30 ±5 mm (distance backsurface of target - plane target surface 50)

diameter of the border line between the target surface portions 49 and50: D_(I) =102 ±5 mm cone angle of the target surface portion 49:β=25°±5°

In connection with the above, the following dimensions are alsopreferred:

external diameter of the target: D_(A) =150 ±5 mm

cone angle of the outer edge :α₁ =50°±5°

raised edge (exterior) : R_(a) =3.8 ±0.2 mm

groove diameter (groove 79) : D_(N) =47.8 ±0.5 mm

groove angel (groove 79) : μ=125° +5°

center bore : diameter D_(B) =40 ±2 mm

Instead of the approximately stepped course of the front surface of thetarget or target surface 76, 50, 49, the outer nose 72 according to FIG.3 can also be omitted and a small target surface 81 can be provided,wherein said small target surface 81 extends parallel with the backsurface 74 of the target and one end of it adjoins an externalcircumference or edge portion 84 and the other end of it adjoins theinclined extending target surface 49 and encloses an angle Σ with it,said angle having a value between 120° and 160°.

According to FIG. 7, the target surfaces 49, 85, 76 can also take azigzag course, i.e. the nose 78 located at the inner area of the bore 83of the target forms with the target surface portion 78' the firstannular groove 79; the inclined extending target surface 49 adjoins saidannular groove 79, and a second annular groove 82, which is formed bythe surfaces 76 and 85, adjoins said inclined extending target surface49. These surfaces 76, 85 enclose the angle α₂ which can have a valuebetween 70° and 175°, and/or the angle β₁ which can have a value between5° and 50°, or 5° and 20°, or between 8° and 12°.

Moreover, according to FIG. 5 it is possible that the inclined extendingtarget surface 41 extends between the two noses 78 and 72 in a convex orconcave manner. The circular target can also have an oval or oblongshape, wherein the arcs of the circle are connected by parallelextending target walls. By means of the sharp-edged or rectangular noses72, as shown in FIG. 8, the electrons are deflected, i.e. in a rightangle (see the vectors B_(H), B_(V) on the magnetic field line of FIG.8). The horizontal component B_(H) holds the electrons on the targetsurface and the vertical component B_(V) holds the electrons in thelateral direction. Thus, the vectors in FIG. 8 show how large the amountof electrons is which are focussed on the target surface, or whichelectrons are accelerated back to the target.

    ______________________________________                                        List of Reference Signs                                                       ______________________________________                                        1       chamber wall                                                          2       sputtering cathode                                                    4       anode                                                                 5       yoke                                                                  6       insulator                                                             7       cooling plate                                                         8       target                                                                9       ring magnet                                                           9'      ring magnet                                                           9"      ring magnet                                                           9'"     ring magnet                                                           10      screw                                                                 11      cable                                                                 12      insulator                                                             13      ring magnet                                                           14      pole shoe                                                             15      cooling ring, cooling body                                            16      cooling channel                                                       17      screw                                                                 18      cooling water connection                                              19      cooling water connection                                              20      hollow screw, pole shoe (fastening device)                            21      yoke plate                                                            22      flange of the cooling finger                                          23      cooling water line                                                    24      cooling water line                                                    25      screw                                                                 26      center mask or center anode                                           27      substrate                                                             28      groove                                                                29      recess                                                                30      chamber surface                                                       31      lower surface                                                         32      clamping ring                                                         33      anode ring                                                            40      back surface of the target                                            41      target surface                                                        42      ring magnet                                                           43      edge area or exterior circumference                                   44      center axis                                                           47      fourth ring magnet                                                    48      exterior circumference                                                49      inclined extending target surface                                     50      parallel extending target surface                                     51      sharp-edged projecting target element                                 52      sharp-edged projecting target element                                 53      flange element                                                        54      flange element of the screw                                           55      exterior circumference of target (8)                                  56      exterior circumference of center mask (26)                            57      lower limit of the target surface                                     58      below the lower limit of pole shoe (14)                               59      in the lower area of the pole shoe (14), and                                  space or chamber                                                      60      truncated-pyramid pole shoe element                                   61      flange element of the pole shoe element or bar                        62      free-standing end of the pole shoe                                    63      lateral wall of truncated-pyramid pole shoe end                               (60)                                                                  64      threaded bolt                                                         65      annular groove                                                        66      annular groove                                                        67      bore                                                                  68      axial bore                                                            69      cooling finger                                                        70      bore                                                                  71      magnetic field lines                                                  71'     magnetic fleld lines                                                  D.sub.1 thickness of target (8), exterior                                     D.sub.2 thickness of target (3), interior                                     A       distance 7-26                                                         P       distance 40-62                                                        ______________________________________                                    

What is claimed is:
 1. A target for a cathode sputtering device forproducing coatings on a substrate (27) by means of a sputtering cathode(2), which can be introduced into a vacuum chamber, said target having acenter axis (44) and being dynamically balanced with respect to thecenter axis (44) and having a back surface (40) and a target surface(41), the target surface (41) being spaced from the back surface andbeing concave as a new target surface, wherein(a) the target surface(41) is formed by at least two concentric target surface portions whichare inclined with respect to each other, the target surface portionsincluding an outer, radially inwardly extending target surface portion(49, 76) enlarging conically away from the center axis in a directionaway from the back surface, and an inner, radially outwardly extendingtarget surface portion (78') narrowing conically toward the center axisin the direction away from the back surface; (b) the target surface (41)has a radially outer edge delimited by an axially projecting edge (72)being inclined with respect to the center axis (44); and (c) aconcentric target surface intermediate portion (50) extending in a planeperpendicular to the center axis (44) is provided between the outertarget surface portion (49) and the axially projecting edge (72).
 2. Thetarget according to claim 1, wherein, between the inner target surfaceportion (78') and the center axis (44) there is formed a cone angle α₃having a value between 10° and 80°.
 3. The target according to claim 2wherein the cone angle α₃ has a value between 20° and 70°.
 4. The targetaccording to claim 2 wherein the cone angle α₃ has a value between 30°and 60°.
 5. The target according to claim 2 wherein the cone angle α₃has a cone angle of 60°.
 6. The target according to claim 1 wherein thetarget has a front surface (75) which lies in a plane that isperpendicular to the center axis (44), and further wherein between theouter target surface portion (49) and the plane there is formed a coneangle β having a value of 15° to 35°.
 7. The target according to claim6, wherein the axially projecting edge (72) forms a cone angle α₁ withrespect to the center axis (44).
 8. The target according to claim 7,wherein the cone angle α₁ of the axially projecting edge (72) has avalue between 20° and 60°.
 9. The target according to claim 8 whereinthe cone angle β₁ has a value between 25° and 55°.
 10. The targetaccording to claim 8 wherein the cone angle α₁ has a value of 50°. 11.The target according to claim 6 wherein the cone angle β has a value of20° to 32°.
 12. The target according to claim 6 wherein the cone angle βhas a value of 23° to 29°.
 13. The target according to claim 6 whereinthe cone angle β has a value of 25°.
 14. The target according to claim1, wherein the outer target surface portion (49) is inclined to enclosean angle Σ having a value greater than 10° with respect to the backsurface (40) of the target an angle μ having a value greater than 10°with respect to the inner target surface portion (78').
 15. The targetaccording to claim 14, wherein the outer target surface portion (49) islocated between the inner target surface portion (78') and the axiallyprojecting edge (72), the angle Σ has a value between 120° and 160° andthe angle μ has a value greater than 90°.
 16. The target according toclaim 15 wherein the angle μ has a value of 125°.
 17. The targetaccording to claim 1 wherein the target surface (41) has a radiallyinner end provided with a dynamically balanced annular groove (79). 18.The target according to 1, wherein the projecting edge (72) has a radialwidth B₃, the target surface intermediate portion (50) has a radialwidth B₂ that is greater than the radial width B₃, and the outer targetsurface portion (49) has a radial width B₁ greater than the radial widthB₃.
 19. The target according to claim 18, wherein the radial width B₁ isapproximately twice as large as the radial width B₂, and twice as largeas the radial width B₃.
 20. The target according to claim 1, wherein thetarget surface has a radially inner edge and, in a direction between theback surface and the target surface, the target has a thickness D₁ atthe radially outer edge and thickness D₂ at the radially inner edge,thickness D₁ is greater than thickness D₂.
 21. The target according toclaim 1, wherein the outer target surface portion (49) is spacedradially inwardly from the target surface intermediate portion (50). 22.The target according to claim 1, wherein the outer target surfaceportion (49) and the target surface intermediate portion (50) areprovided between inner and outer axially projecting edges (51, 52; 78,72) of the target surface.
 23. A cathode sputtering device for producingcoatings on a substrate (27) by means of a sputtering cathode (2), whichcan be introduced into a vacuum chamber, comprising: a target accordingto claim 1, wherein the target has an exterior circumference (55); atleast one first ring magnet (9 or 13) located adjacent the back surface(40) of the target; and at least one second ring magnet (47) disposedadjacent the exterior circumference (55) and below the first ring magnet(9 or 13).
 24. The device according to claim 23, wherein the targetsurface has a lower limit (57) and the second ring magnet (47) islocated slightly above or below the lower limit (57).
 25. The deviceaccording to claim 24, wherein the lower limit (57) extends parallel tothe back surface (40) and the second ring magnet (47) is locatedslightly below or outside the lower limit (57).
 26. The device accordingto claim 23, further comprising pole shoes (14) having a lower limit(58), and wherein the second ring magnet (47) ends slightly below oroutside the lower limit ( 58) of the pole shoes (14).
 27. The deviceaccording to claim 23, wherein the second ring magnet (47) extendsconcentrically with the center axis (44) of the target.
 28. The deviceaccording to claim 23, farther comprising a pole shoe (14) having alower limit (58) and wherein the target surface has a lower limit (57)and the lower limit (58). of the pole shoe (14) is at a greater distanceP from the back surface (40) of the target than is the lower limit (58)of the target surface.
 29. The device according to claim 23, furthercomprising a pole shoe (14) having a lower area provided with an annularspace or chamber ( 59) or two spaced apart flanges or bars (61).
 30. Thedevice according to claim 23, further comprising a pole shoe (14) havinga lower portion and an exterior circumference, and wherein the lowerportion of the pole shoe (14) extends to the exterior circumference ofthe pole shoe (14) and consists of a pole shoe element (60) which tapersto form a truncated pyramid.
 31. The device according to claim 30,wherein the pole shoe element (60) has a freestanding end (62), the poleshoe (14) has a flange element (61) which makes a transition into thepole shoe element (60), and the flange element (61) is wider than thefreestanding end (62) of the pole shoe (14).
 32. The device according toclaim 31, wherein the flange element (61) of the pole shoe (14) extendsparallel with the back surface (40) of the target.
 33. The deviceaccording to claim 23, farther comprising a pole shoe (14) having alower portion and an exterior circumference, and wherein the lowerportion of the pole shoe (14) extends to the exterior circumference ofthe pole shoe (14) and consists of a pole shoe element (60) which has afreestanding end (62) having a front face, and the pole shoe element(60) further has an inclined extending lateral wall (63) which tapers toform a truncated pyramid, and farther wherein the front face of thefreestanding end (62) of the pole shoe (14) and the inclined extendinglateral wall (63) enclose an angle α having a value between 10° and 60°.34. The device according to claim 33 wherein the angle a has a valuebetween 20° and 50°.
 35. The device according to claim 33 wherein theangle a has a value between 25° and 45°.
 36. The device according toclaim 23, further comprising a pole shoe (14) having a lower portion andan exterior circumference, and wherein the lower portion of the poleshoe (14) extends to the exterior circumference of the pole shoe (14)and consists of a pole shoe element (60) which has an inclined extendinglateral wall (63) which extends parallel to the axially projecting edge(72) of the target surface (41).
 37. The device according to claim 23wherein the at least one first ring magnet comprises an inner ringmagnet (9) and an outer ring magnet (42) having a larger diameter thanthe inner ring magnet (9), the inner ring magnet and the outer ringmagnet being disposed adjacent to the back surface (40) of the target.38. The device according to claim 37, wherein the inner ring magnet andthe outer ring magnet are arranged on a common transverse plane.
 39. Thedevice according to claim 37, further comprising en element constitutedby one of: a center mask, or a center anode, or a cooling finger, theelement having an exterior circumference (56) that is spaced radiallyinwardly from the target surface, and wherein the inner ring magnet (9)is located adjacent to the exterior circumference (56) of the elementand the outer ring magnet (42) is located adjacent to the exteriorcircumference (55) of the target.
 40. The device according to claim 37,further comprising a third ring magnet (13), which surrounds the innerring magnet (9) and the outer ring magnet (42).
 41. The device accordingto claim 40, further comprising a yoke (5) and wherein the third ringmagnet (13) adjoins a side of the yoke (5).
 42. The device according toclaim 40, wherein the inner, outer and third ring magnets (9, 42, 13)are mounted to be dynamically balanced with respect to the center axis(44) of the target.
 43. The device according to claim 37, furthercomprising a cooling plate (7) provided with annular grooves (65, 66)and wherein the inner ring magnet (9) and the outer ring magnet (42) arearranged in the annular grooves (65, 66).
 44. The device according toclaim 37, further comprising a pole shoe (14) having an upper portionand a yoke (5), and wherein the outer ring magnet (13) is aligned withthe upper portion of a pole shoe (14) parallel to the center axis (44)and is disposed between the yoke (5) and the upper portion of the poleshoe (14).
 45. The device according to claim 37, wherein the inner ringmagnet (9) and the outer ring magnet (42) are located radially inwardlyof the external circumference (55) of the target.
 46. The deviceaccording to claim 37, further comprising a third ring magnet (13),which surrounds the inner ring magnet (9) and the outer ring magnet (42)and wherein the third ring magnet (13) is at a greater distance from theback surface (40) of the target than are the inner ring magnet and theouter ring magnet.
 47. The device according to claim 37, furthercomprising a third ring magnet (13), which surrounds the inner ringmagnet (9) and the outer ring magnet (42), and a fourth ring magnet (47)which surrounds the exterior circumference (55) of the target.
 48. Thedevice according to claim 23, further comprising a cooling plate (7) anda flange element (54) of a fastening device (20) connected with thetarget, and wherein the target has an inner edge area and furtherincludes an annular flange element (53) extending concentrically withrespect the center axis (44) and provided at the inner edge area of thetarget, said annular flange element (53) being clamped between thecooling plate (7) and the flange element (54) of the fastening device(20).
 49. A target for a cathode sputtering device comprising an annularbody having a center axis, an exterior cylinder surface, a back surface(40) perpendicular to the center axis (44) and a concave target surface(41) as a new target surface, wherein the target surface (41) isdynamically balanced with respect to the center axis and comprises:(a) aconical target surface portion (49) which is inclined by an angle β withrespect to a plane (75) perpendicular to the center axis (44); (b) aninner edge portion (78) having a truncated conical surface (78') that isinclined by an angle α₃ with respect to the center axis and whichadjoins the conical target surface portion (49) in order to form anessentially V-shaped groove (79); and (c) a target surface intermediateportion (50) extending in a plane perpendicular to the center axis (44)and making a transition into the conical target surface portion (49).50. The target according to claim 49, wherein the target surface furthercomprises a conical edge portion (76) which is inclined by an angle α₁with respect to the center axis (44) and extends radially to theexterior cylinder surface, and the target surface intermediate portion(50) makes a transition into the conical edge portion (76).